Prince Jones v US

[Robert J. Hansen]

Good news for US citizens: _Prince Jones v US_ was decided Thursday.
The important text from the opinion is recreated here, and the
implications for encrypted email follow.

* * * * *

But in addition to the fact that people reasonably value and hope to
protect the privacy of their location information, what necessitates our
conclusion is the _method_ by which the government obtained the location
information in this case. Unlike in a situation in which the government
determines a person's location through visual surveillance or by
employing the older generation of tracking devices, it cannot be argued
that "the information obtained by [the government] in this case was ...
readily available and in the public view". The cell-site simulator
employed in this case gave the government a powerful person-locating
capability that private actors do not have and that, as explained above,
the government itself had previously lacked -- a capability only
superficially analogous to the visual tracking of a suspect. And the
simulator's operation involved exploitation of a security flaw in a
device that most people now feel obligated to carry with them at all
times. Allowing the government to deploy such a powerful tool without
judicial oversight would surely "shrink the realm of guaranteed privacy"
far below that which "existed when the Fourth Amendment was adopted". It
would also place an individual in the difficult position either of
accepting the risk that at any moment his or her cellphone could be
converted into tracking device or of forgoing "necessary use of" the
cellphone. We thus conclude that under ordinary circumstances, the use
of a cell-site simulator to locate a person through his or her cellphone
invades the person's actual, legitimate, and reasonable expectation of
privacy in his or her location information and is a search.

* * * * *

The above is taken from the opinion -- citations omitted.  But it
appears to me this logic is immediately applicable to many different
kinds of surveillance: namely, if it involves security flaws in common
everyday technologies which millions of Americans entrust with their
secrets and who really cannot reasonably avoid using... then it needs a
warrant.

The implications for electronic privacy in the United States should be
clear.  This is a really good development.  :)